Category Archives: Networking

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Ends up, we are all like a lazy sack of potatoes, at least when it comes to RF. Boeing calls it Project SPUDS or rather Synthetic Personnel Using Dielectric Substitution. Apparently they are good substitute for real human bodies when testing wireless networks on planes. Fill the seats with sacks of potatoes and test away.

The Verge has an interesting article, video and photo essay on the repair efforts at Verizon’s Broad Street facility after Hurricane Sandy. It’s amazing to see the mess of copper. Sadly, even before Hurricane Sandy this was hardly awesome infrastructure, it’s generations old copper. The upside is it’s now being modernized, the downside is that this is a real drag for anyone who relies on that facility.

I didn’t even realize, but the mandate to go IPv6 has passed for the U.S. Government. Not that it really mattered anyway. Until consumer devices ship IPv6 ready and enabled, and ISP’s start rolling out IPv6, this is just an exercise is what will hopefully save work later on.

Seems most Government websites I’ve checked so far that are IPv6 are using CDN’s to provide IPv6 connectivity. I’m betting behind the scenes it’s all IPv4 still.

A nice little scoop from Apple Insider about iOS 6 shipping with a new setting. Wi-Fi Plus Cellular it will allow your phone to fall back to cellular when a Wi-Fi access point is slow. A rather nice little enhancement.

I’d actually love to see Wi-Fi be geofenced, so that it will automatically enable itself in certain locations. I don’t need Wi-Fi on all the times, but there are certain locations where iOS devices could utilize it. Why should I need to toggle it myself if the device knows where it is? I’d love if my phone knew it had access to Wi-Fi at home and could switch automatically when I’m home. It seems like this would be simple enough to do right. Apple does all the pieces already, it’s just a matter of doing it together.

It’s here! World IPv6 Launch begins June 6 2012 00:00:00 UTC. The future of the Internet (and the beginning of the death of NAT).

I’ve started enabling IPv6 on my websites including this one, which is already seeing a few IPv6 hits. I expect to see that climb over time. I’ve noticed Facebook turned on IPv6 recently. Google is expected to at any moment. A handful of bugs limit me from flipping the switch on a few more sites, but I hope to get that resolved soon enough. Still better than my 2010 projections.

If you’re unsure if you’re internet connection supports IPv6 yet, you can find out at:AmIUsingIPv6.com

Netflix is trying to reduce it’s dependency on CDN’s by peering directly with ISP’s and with a new hardware appliance ISP’s can host on their own network to offload traffic. The peering option is pretty strait forward. The appliance however is interesting. Netflix is actually quite transparent about what they are doing, so I thought I’d dig in and take a little look since they are sharing:

Hardware

Netflix says right up front they were influenced by Backblaze, and their appliance is actually quite similar in many respects. The difference is that Netflix does need a bit more CPU and Network IO and a little less storage. That balance is pretty achievable. The appliance must be a tad on the heavy side as this is a pretty heavily packed server.

Essentially the hardware is a Supermicro mATX board and a bunch of SATA hard drives in a custom 4U enclosure. There are 2 16 port LSI SAS controllers for 32 drives and 4 drives presumably running directly off the motherboard. Hitachi Deskstar or Seagate Barracuda drives. Nothing fancy here. An interesting tidbit is there are 2 x 512 GB “flash storage” (presumably SSD) for logs, OS, popular content. I’d assume those two are running in RAID 0 as one volume. They are managing the spinning disks in software RAID so they can handle failures.

Software

FreeBSD is the OS of choice. Not sure if this software RAID they are doing is something they cooked up or something already out there. Another interesting note is they are using nginx for a web server and are using http for moving content. Huge win for nginx and says a lot for it’s abilities as a web server. It also sounds like Netflix is a customer of NGINX, Inc.

The idea of an appliance on the ISP end isn’t new. CDN’s generally live close, not in the ISP’s network. On the TV side Weather Channel has done this for ages via the little known WeatherSTAR appliances (pic). They sit at the headend and get weather from TWC. They then output local weather reports as a video for the cable provider to insert. The WeatherSTAR appliance like the Netflix appliance is essentially 0 maintenance. It just lives locally and serves it’s master remotely.

It’s nice that they’ve been as open as they have about what they are building. They also have an engineering blog worth keeping an eye on.

CHARLESTON, W.Va. — Nobody told Hurricane librarian Rebecca Elliot that the $22,600 Internet router in the branch library’s storage closet was powerful enough to serve an entire college campus.
…
The high-end router serves four public computer terminals at the small library in Putnam County.

It goes on to define them as Cisco 3945’s. These are reasonably large (in terms of Cisco’s lineup) high capacity routers. Given 4 computer terminals in a library, a cheap Linksys box (also Cisco) would have likely done the job just as well, for under $100.

I don’t think that router provides CIPA compliant filtering either, so I’m guessing they are doing it via software on the computers connected, or they have a gateway appliance of some sort.

It gets even more amusing:

Gianato said the T1 cards have other uses — video conferencing, wireless Internet and “voice over Internet protocol.”

A T1 (DS1) line is 1.544 Mbit/s. Granted unlike most broadband services this is a direct private line and thus you get the full 1.544 Mbit/s, but still this is 2012. You’re unlikely to be using such low capacity for those services in any meaningful way. You’d likely get better performance with a residential cable modem these days.

Took only a year and it seems the Dutch passed a relatively comprehensive net neutrality law after KPN’s proposal to break net neutrality. The US will be forced to face this debate one way or another soon enough. Our economy and lives are being very reliant on those pipes.

Wi-Fi network use will nearly double in homes around the world come 2016, according to new Strategy Analytics research. Already used in some 439 million households worldwide, equivalent to 25% of all households, Wi-Fi home network penetration will expand to 42%, reaching nearly 800 million by 2016, according to the “Broadband and Wi-Fi Households Global Forecast 2012” report.

It also mentions that 61% of US households have Wi-Fi.

Having had Wi-Fi now for a decade (since late 2001), I can’t imagine life without it anymore. It’s liberating being able to put a laptop anywhere and get online at high-speed. Devices like the iPad just make it more so.

Wi-Fi is easy to take for granted. It’s becoming a utility like electricity and water. You just expect it to be there and work when you want it.

I’ve been digging into Mac OS X’s sometimes unstable WiFi connections for a while now, and have come to the conclusion that the Broadcom drivers in Mac OS X 10.6+ are either too fussy or just buggy in particular when dealing with 802.11n.

Apple’s iOS drivers seem to be different as few people see the same issues across Mac OS X and iOS. On the hardware side, the iPad 3 and iPhone 4S use a Broadcom BCM4330, while the slightly older iPhone 4 uses a BCM4750. MacBook, MacBook Pro, Air use a Broadcom BCM4331 these days. Some older ones (pre-2010 I believe) used Atheros AR5008. As you can see the hardware is pretty similar suggesting software as the discrepancy. Despite using a Darwin based OS it makes sense to have slightly different drivers. These devices have very different needs in terms of data usage patterns and power consumption. iOS devices seem to use less power than their OS X based counterparts. That makes perfect sense. The question is how does this impact connectivity and what can we do about it?

Apple has recommendations for iOS. For the most part these are universally good recommendations, however I’ve found a few things to be different:

802.11 a/b/g/n – If you’ve got a broad set of clients, without question seek out a simultaneous dual-band wireless router. Not dual-band, simultaneous dual-band. This will save you a lot of headache and ensure good performance. Two radio’s are better than one.

Channel – Apple says to set it to “auto”, however I’ve found if there are several access points on other channels nearby this can be troublesome for OS X based clients on 802.11n in the 5 GHz spectrum. You’re best off setting it to the most open frequency and leaving it if you experience problems. This alone will likely resolve many (if not all) connectivity issues in my experience. 2.4 GHz seems to do better in auto channel. I’m not entirely sure why this is, however I suspect it has to do with power saving strategies employed by the driver. This seems to be even more problematic with 40 MHz channel width, which sort of makes sense given they are related.

Set 5 GHz channel width to 20/40… maybe – Apple says to set the 5 GHz channel width to 20/40 MHz if supported because not all devices support 40 MHz, and this is most compatible. If you’ve got simultaneous dual band, you can consider setting it to 5 GHz 802.11n only with 40 MHz channel width and set the other radio set to 802.11b/g 2.4 GHz / 20 MHz serve as adequate backwards compatibility for non-40 MHz devices. I’ve run things both ways, and IMHO either will serve most needs well. Just depends what devices you are supporting.

This is pretty obvious in retrospect. The 5 GHz spectrum seems to have some funny business with channel selection and this can be solved by just being more strategic about your usage. If you’ve got an Apple device being fussy with network connections, this is the first thing to play with.